Air cleaner

ABSTRACT

The present invention relates to engine manufacture. An air cleaner which comprises a housing (1) with an air-supply pipe (2) forming an annular clearance (3). A main filtering member (5) is placed in the clearance (3) and in close vicinity to the opening (13) of the air-supply pipe (2) and additional filtering member (14). According to the invention the filtering member (14) has a recess (15) which is coaxial to the pipe (2) on the surface (16). The size of the recess (15) on the surface (16) is greater than the diameter of the pipe (2). 
     It is preferably to use the air cleaner in an engine operating in unfavorable conditions with vapors of oil and soot.

TECHNICAL FIELD

The present invention relates to the engine manufacture and, morespecifically, to automobile and tractor internal-combustion engines and,more particularly, to air cleaners.

BACKGROUND OF THE INVENTION

Known in the art is an air cleaner (V. E. Maev, N. N. Ponomarev."Air-Cleaners for Automobile and Tractor Engines", 1971,"Machinostrojenie" Publishing House, (Moscow), p. 76-77) comprising acylindrical housing positioned vertically, wherein en air-supply pipe ispositioned coaxially therewith with the formation of an annularclearance between the outside surface of the tube and the inside surfaceof the housing. In the clearance there is provided a filtering membersuch as Kapron fibres placed into a rigid ring-shaped perforatedcassette. The cassette height is less than the length of the air-supplypipe in the housing. In the direction of the air movement after thecassette an air-vent pipe is positioned which is directly connected tothe inlet pipe of internal-combustion engines. The lower part of thehousing which is its bottom is filled with an oil so that the outletopening of the pipe is positioned above the level of the oil.

On the bottom of the housing coaxially with the pipe in the nulk of theoil a cup-like bath also filled with the oil is mounted. A jet of dustedair coming out of the air-supply pipe passes into the bath and displacesa layer of the oil therefrom by way of a dynamic head, and atomizes it.Drops of the atomized oil are intermixed with the air jet and wet thelower layers of the filtering member. The dusted air comes in contactwith the oil which envelopes the dust particles and agglomerates them.Heavy particles of the dust with the excess of the oil get drained fromthe surface of the filtering member back into the lower part of thehousing. The remaining dust particles with the air current penetrateinto the lower oil-impregnated layers of the filtering member and getdeposited on the fibres of the latter.

However, the dripping of the oil over the surface is non-uniform. Inoperation of an automobile or a tractor with such an air-cleaner underconditions of a rugged terrain there can take place inclinations of theair-cleaner which result in the situations where the oil excessivelywets some regions of the filtering member and leaves other regionspractically unwetted. The fibres of the filtering member only slightlywetted with the oil render a lower resistance to dust particle which,eventually, pass through the filtering member into the engine causing anearly wear thereof. The excess of the oil from the abundantly wettedfibres also passsed into the engine with the dust, thus impairing itsoperation and causing wear too.

Also known is an air-clearer (FR, A 1536325) comprising a cylindricalhousing, wherein substantially coaxially therewith an air-supply pipe isprovided with the formation of a clearance between the outside surfaceof the tube and the inside surface of the housing and with a mainfiltering member positioned in said clearance. After the main filteringmember along the direction of the air current an air-vent pipe islocated communicating with the cavity of an internal-combustion engineand close to the lower end face of the housing on the side of the outletopening of the pipe an additional filtering member is positioned. In thelower part of the housing between the end face and the additionalfiltering member oil is provided. The additional filtering member has athrough opening coaxial with the air-supply pipe but with the sizethereof considerably inferior to the air-supply pipe diameter.

In the engine operation a portion of the current of atmospheric airpassing via the air-supply pipe penetrates into the through opening ofthe additional filtering member and, passing therethrough, contacts withthe layer of an oil positioned under the additional filtering member inthe lower part of the housing. The head of the dusted air is ratherstrong and pores of the additional filtering member constitute 1/2 ofits volume, wherefore the oil drops pass through this filtering memberand wet the air current passing right from the air-supply pipe into themain filtering member.

In such an air-cleaner upon the movement of a car or a tractor over arugged terrain which is usual in their exploitation, the additionalfiltering member prevents an excessive spilling of the oil and reducesits ejection into the engine. However, a permanent change of the angleof inclination of the oil level to the air current outgoing from thepipe results in an insufficient and non-uniform spraying of the oil and,accordingly, a non-uniform wetting of the main filtering member, thusresulting in an increasing probability of penetration of dust particlesinto the engine, i.e. the efficiency of the air cleaning is lowered.Furthermore, at high angles of inclination or at a sharp change in themovement speed of a car or a tractor, running over some obstacles andthe like, a portion of the oil is delivered through the additionalfiltering member into the main one, thus excessively saturating thelatter with the oil which can be entrained, along with dust, andpenetrates into the engine, which results in an invensive wear of thelatter.

All these factors are detrimental to the dusting capacity of theair-cleaner which is determined by the amount of dust trapped by thefiltering members. Besides, the presence of a considerable volume of theoil in the lower part of the housing entails a strictly verticalposition of the air cleaner which is not always rational from the pointof view of a compact arrangement thereof in the body of a car or atractor.

SUMMARY OF THE INVENTION

The present invention is directed to the provision of an air-cleanerwith such a design of the additional filtering member and itsarrangement in the housing of the air cleaner which would make itpossible to increase dust capacity of the filtering members whileavoiding the necessity of pouring oil into the air cleaner, thusenabling eventually mounting the air cleaner at any angle to thehorizontal.

The present invention resides in that in an air-cleaner comprising ahousing with an air-supply pipe positioned inside said housingsubstantially coaxially therewith with the formation of a clearancebetween the outside surface of this pipe and the inside surface of saidhousing, wherein a main filtering member is located, with an air-ventpipe positioned after it in the direction of the air movement and closeto the housing end face on the side of the outlet opening of the pipeand additional filtering member is provided, according to the presentinvention, in said additional filtering member a recess is madesubstantially coaxially with the pipe and facing the outlet opening ofsaid pipe with its maximum size on the surface adjacent to the outletopening of the pipe is greater than the diameter of the latter.

To improve the efficiency of dedusting of the air, it is advisable thatthe maximum size of the recess on the surface of the additionalfiltering member be within the range of from 1.10 to 2.45 of the pipediameter and the recess depth be within the range of from 0.3 to 4.0 ofthe pipe diameter.

To still further improve the efficiency of air cleaning from dust, it ispossible that the recess surface be made corrugated with alternatingprotrusions and depressions.

To simplify the process of manufacture of the air cleaner it ispreferable that the height of the additional filtering member be suchthat its surface facing the pipe opening be contacting the surface ofthe main filtering member facing the recess.

To increase the dust capacity of the additional filtering member, athrough duct should be preferably made therein.

The air cleaner according to the present invention, owing to the use ofan additional filtering member with a recess substantially coaxial withthe air-supply pipe makes it possible to improve the efficiency of dustcleaning of the air and to increase the dust capacity of the air cleanerand, hence, to extend the duration of its operation till an ultimateresistance value, since the majority of dust particles upon turning ofthe air current in the recess under the effect of centrifugal forceswill deposit in said additional filtering member, thus reducing theamount of dust passing into the main filtering member.

Furthermore, the presence of the recess in said additional filteringmember makes it possible to ensure such efficiency of dust cleaning ofthe air that the necessity of pouring an oil into the filtering memberis avoided. This, in turn, enables a more compact mounting of the aircleaner in any position.

The design of the air cleaner according to the present invention makesit possible to considerably reduce the oil consumption.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further illustrated by the description ofparticular, but not limiting, embodiments thereof with reference to theaccompanying drawings, wherein:

FIG. 1 is a general view of the air cleaner according to the presentinvention, in elevation;

FIG. 2 is an isometric view of the additional filtering member;

FIG. 3 is an embodiment of the additional filtering member shown in FIG.2, elevation view;

FIG. 4 is an embodiment of the air cleaner according to the presentinvention, elevation view;

FIG. 5 is a cross-section V--V in FIG. 4;

FIG. 6 is still another embodiment of the air cleaner according to thepresent invention, elevation view.

BEST MODE FOR CARRYING OUT OF THE INVENTION

The air cleaner shown in FIGS. 1 and 2 comprises a cylindrical housing 1consisting of two detachable parts 1a and 1b and manufactured from asheet steel. Positioned inside the housing 1 and substantially coaxiallytherewith is an air-supply pipe 2 with the formation of a clearance 3between the outside surface of this pipe 2 and the inside surface of thehousing 1. In the present embodiment of the air cleaner the pipe 2consists of two detachable parts 2a and 2b the joint therebetween beingsealed by means of a sealing annular gasket 4 made from a resilientmaterial such as rubber. A main filtering member 5 of a fibrousstructure (e.g. from Kapron fibres placed inside a cylindrical metalliccassette 6) is positioned in the clearance 3. The cassette 6 has anannular outside collar 7 onto which a V-like sealing ring is put. Thecollar 7 with the ring 8 is located between the detachable parts 1a and1b of the housing 1 which are secured to one another by means of, e.g.spring clamps (not shown in the drawing).

At the end faces of the cassette 6 openings are made for passing air(along the arrow A) through the packing of the filtering member 5. Afterthe filtering member 5 in the direction of the air movement (arrow A)close to the upper end face 10 of the housing 1 an air-vent pipe 11 isprovided which communicates with the inlet pipe of aninternal-combustion engine (not shown in the drawing). Close to theother end face 12 of the housing 1 on the side of the outlet opening 13of the pipe 2 an additional filtering member 14 is located which is madeof, for example, an elastic open-pore polyurethane foam.

A recess 15 is made in the additional filtering member 14 substantiallycoaxially with the pipe on the side facing the outlet opening 13 of thepipe 2. The maximum size of the recess 15 on the surface 16 of theadditional filtering member 14 adjecent to the outlet opening 13 of thepipe 2 exceeds the diameter d of the latter and is equal to 1.10-2.45 ofthe diameter d of the pipe 2. In the case where the size D of the recess15 on the surface 16 is more than 2.45 of the pipe diameter d, dustparticles would substantially not reach the walls 17 of the recess 15.The dust settling efficiency in the additional filtering member 14 inthis case will sharply drop, thus resulting in the penetration of dustinto the main filtering member 5.

In the case where the size D of the recess 15 on the surface 16 of theadditional filtering member 14 is less then 1.1 of the pipe 2 diameterd, due to an insufficient surface area of the recess 15 this surfacewill become rapidly clogged with dust, thus hindering penetration of thedust particles inside the additional filtering member 14. This will alsoresult in an increased rate of penetration of dust into the mainfiltering member 5.

In the present embodiment the size D of the recess 15 on the surface 16is equal to two diameters of the pipe 2, i.e. D=2d.

The depth D of the recess 15 is varied within the range of from 0.3 to4.0 diameter d of the pipe 2.

In the case where the depth H is above 4.0 diameters d of the pipe 2,this results in a considerable increase of the overall dimensions of theair cleaner and the dust particles will not reach, the bottom 18 of therecess 15.

In the case where the depth H of the recess 15 is less than 0.3 diameterd of the pipe 2, the total area of the surface of the recess 15 isinsufficient.

In the instant embodiment the depth H of the recess 15 is equal to thediameter d of the pipe 2, i.e. H=d.

In the clearance 3 between the main filtering member 5 and the air-ventpipe 11 one more filtering member 19 having a ring-like shape ispositioned. The density of this member 19 is, as a rule, higher thanthat of the filtering members 5 and 14.

The recess 15 of the additional filtering member 14 shown in FIG. 2 ismade as a tapered cone expanding to the surface 16 and having inclinedwalls 17. However, the shape of the recess 15 can be different, forexample cup-like, cylindrical, more sophisticated, and the like.

In the embodiment of the additional filtering member 14 shown in FIG. 3of the accompanying drawing, the wall 17' of the recess 15 is madecorrugated with alternation of protrusions and depressions so that saidprotrusions and depressions are oriented parallel to the surface of theadditional filtering member 14.

The embodiment of the air cleaner shown in FIGS. 4 and 5 differs fromthe air cleaner shown in FIGS. 1 and 2 in that the main and additionalfiltering members 5 and 14 respectively are made as a whole, i.e. thatthe height H₁ of the additional filtering member 14 is such that itssurface 16 facing the opening 13 of the pipe 2 contacts the surface 20of the main filtering member 5 facing the recess 15. In this case bothfiltering members 5 and 14 are placed into a common metallic cassette 6provided with an insert 21 of a reticulated structure to preventfalling-out of Kapron fibres into the cavity of the recess 15. Thebottom 18 of the recess 15 provided with openings 21"a".

In the air cleaner embodiment shown in FIG. 6 of the accompanyingdrawing an outlet duct 22 is made in the additional filtering member 14at the centre of the bottom of the recess 15 which duct communicates thespace occupied by the recess 15 with the space 23 between the insidewall of the housing 1 and the surface of the additional filtering member14.

Described hereinbefore have been the preferred embodiments of thepresent invention intended for illustration thereof, but it is clear fora person skilled in the art that various modifications could be madetherein without, however, falling beyond the scope of the appendedclaims.

The embodiment of the air cleaner shown in FIGS. 1 and 2 operates in thefollowing manner. A car or tractor engine (not shown) is energized. Astream of dusted atmospheric air (arrow A) due to a reduced pressure inthe cylinders of the internal-combustion engine communicating with theatmosphere through the air cleaner is sucked into the air-supply pipe 2located inside the housing 1. At the outlet from the opening 13 of thepipe 2 the air stream passes into the recess 15 of the additionalfiltering member 14 and turns in the opposite direction. In this case aportion Q₁ of the air stream penetrates into the additional filteringmember 14 through the air-permeable wall 17 of the recess 15 and,turning therein, comes out through its surface 16. The dust particles ofthe portion Q₁ of the stream pass together with the air inside thefiltering member 14. In doing so, the dust particles are deposited atthe account of both usual filtration and due to the deviation of theparticles from the line of current under the effect of centrifugalforces towards the zones of the member 14 adjacent to the housing 1.

Another portion Q₂ of the air stream contacting the inside walls of thepipe 2 follows the path of the least resistance--into the clearancebetween the outlet opening 13 of the pipe 2 and the recess 15 of theadditional filtering member 14. The dust particles of the portion Q₂from the air stream, while deviating from its path under the effect ofcentrifugal forces, pass onto the surface of the walls 17 of the recess15. To improve deposition of dust particles, the additional filteringmember 14 is wetted with an oil during its assembling.

To intensify the dust deposition from the portion Q₂ of the air stream,the surface of the wall 17 (FIG. 3) of the recess 15 is made corrugatedwith alternating protrusions and depressions.

The dust particles non-trapped by the filtering member 14 (FIGS. 1 and2) pass towards the surface 20 of the main filtering member 5. All thedust particles remaining in the portions Q₁ and Q₂ of the air stream aresubstantially deposited on the fibres of this filtering member 5, but inthe case of tearing-off of the aggregated particles a filtering member19 preliminarily impregnated with an oil is provided in their path.

Therefore, upon penetration of the air stream into the air-vent pipe 11,said stream becomes substantially fully exempted from dust.

The air cleaner shown in FIGS. 4 and 5 operates in a manner similar tothat described for the embodiment thereof shown in FIGS. 1 and 2, withthe only difference that filtration therein occurs mainly according tothe mechanism described for the stream Q₁. It is advisable that thefiltering member 14 be preliminarily wetted with an oil, surplus ofwhich runs down through the openings 21"a".

The operation of the air-cleaner shown in FIG. 6 of the accompanyingdrawing differs from that of the air-cleaner shown in FIGS. 1, 2, 4 and5 in that the heaviest dust particles upon turning in the recess 15penetrate, under the effect of centrifugal forces, into the space 23limited by the inside wall of the end face of the housing 1 and by thesurface of the additional filtering member 14.

All the above-described embodiments of the air cleaner according to thepresent invention operate in much the same manner when inclined at anyangle to the horizontal.

The air cleaner according to the present invention and the prior art aircleaner have been subjected to stand tests.

The dimensions and the structure arrangement of the main filteringmember 5, of the additional filtering member 14 and 19 in both testembodiments of the air cleaner were the same. In the additionalfiltering member 14 of the air cleaner according to the presentinvention a cylindrical recess was made with the diameter of 1.1 to 2.45of the pipe diameter and the depth was within the range of 0.3 to 4.0diameters of the pipe.

The tests have been carried out on a motor-free stand for testing aircleaners with the use of an air stream containing particles of quartzdust with the specific surface area of 5.600 cm² /g at the air streamspeed of movement through the member 5 equal to 2.2 m/s. The dustcontent in the air was 0.4 g/m³.

The tests have shown that the dust capacity (the amount of dust trapped)of the air cleaner was by 2.2 times higher and the mean factor of dustpassage equal to the ratio of the amount of the passed dust to the dustamount passed into the air-supply pipe is by 2 times lower.

INDUSTRIAL APPLICABILITY

The use of the air cleaner according to the present invention ispossible in carburettor or diesel internal-combustion engines, as wellas in other systems of filtration of air and gases.

It is preferable to use the air cleaner for replacing dry-type aircleaners with cardboard filtering members and for air-cleaners with anoil bath, both operating under unfavourable conditions--with vapours ofan oil and with carbon black contained in the air.

What we claim is:
 1. An air cleaner comprising a housing (1) with anair-supply pipe (2) positioned substantially coaxially thereto with theformation of a clearance (3) between the outside surface of this pipe(2) and the inside surface of the housing (1) with the main filteringmember (5) placed in the clearance (3), an air-vent pipe (11) positionedafter the main filtering member (5) in the direction of the airmovement, an additional filtering member (14) located close to the endface (12) of the housing (1) on the side of the outlet opening (13) ofthe pipe (2), characterized in that a recess (15) is made substantiallycoaxially to the pipe (2) on the side facing the outlet opening (13) ofthe pipe (2) with the maximum size (D) of the recess (15) on the surface(16) adjacent to the outlet opening (13) of the pipe (2) is greater thanthe diameter (d) of the latter.
 2. An air cleaner according to claim 1,characterized in that the maximum size (D) of the recess (15) on thesurface (16) of the additional filtering member (14) is equal to1.10-2.45 of the pipe (2) diameter (d) and the depth of the recess (15)is equal to 0.3-4.0 diameter (d) of the pipe (2).
 3. An air cleaneraccording to claim 1, characterized in that the surface of the recess(15) is made with alternating protrusions and depressions.
 4. An aircleaner according to claim 1, characterized in that the height (H) ofthe additional filtering member (14) is such that its surface (16)facing the pipe (2) opening (13) contacts the surface (20) of the mainfiltering member (5) facing the recess (15).
 5. An air cleaner accordingto claim 1, characterized in that a duct (22) is made in the additionalfiltering member (14).